Automatic clamp



A. l. SCHIFF Nov. 19," 1929.

AUT'OMATIC CLAMP Filed March 7, v1929 11v VENTOR. 4/ er) Jab/ff ATT NEY" Patented Nov. 19, 1929 ALBERT I. SGHIFF, OF NEW YORK, N. Y.

AUTOMATIC CLAMP Application filed March 7,

This invention is an automatic clamp adapted for various uses in the several arts where it may be desired-to detachably associate one part with another in clamped relation.

Speaking generally, the invention relates to that type of clamping device wherein a cam action is utilized to effect the clamping function. Devices of this broad generic type have heretofore been suggested, but they have been open to numerous objections which have rendered their practical application unsatisfactory.

My experience with devices of this general character is that the clamping action must be of a positive nature so as to obviate inadvertent displacement of the clamp part with reference to the clamping parts, and a further important requisite is that the clamp part may be readily moved into clamped relation with the clamping parts. In all of the prior devices of which I am aware, it has been necessary in order to move for example a broom handle into cooperative relation with the clamp to introduce the handle of the broom with an accompanying longitudinal movement. That is to say, the upper end of the broom must be introduced into the clamp either by lifting the movable jaw out of the way manually or by pushing the broom handle'up from the bottom between the; clamp ing jaws.

In broom closets and other, places where clamps of this sort have been used, the space is frequently such as notto permit ofthis latter operation and it therefore becomes necessary to actually lift the movable jaw manually in order to introduce a broom;

I have referred by way of example to a broom as associated with this type of clamp, because this general type of clamp has been usually intended for such use. I wish it understood, however, that the present invention is not limited to this use, but that it is susjceptible to widely varying applications. For

example, it may be rigidly mounted upon a suitable support to hold articles in a detachable manner, or, on the other hand, it may be associated with some part to be supported and function in connection with a suitable stand- 1929. Serial No.' 345,001.

ard constituting a support for the clamp and the adjunct associated therewith. The object ofthe present invention is to provide a clamp operating on cam principles and freefrom the objections which have heretofore been universally prevalent in cam action clamps as heretofore produced;

Speaking generally, the clamp of the present invention embodies a suitable base with which is associated a fixed jaw of suiiicient extent to form a relatively extensive support for the article to be clamped as opposed to the clamping action of the movable jaw. The movable jaw is in the form of a pivoted member having a curved clamping face, the curvature of which is on progressive radii. The movable jaw is mounted upon a fiXed pivot and is thereby susceptibleof pivotal movement,the curvature of the movable jaw being such as to have a progressive clamping action incident to progressive pivotal 'movement of the movable jaw.

In other words, the relation between the fixed and movable jaws is such that the clamping action becomes greater as the movement of the movable jaw proceeds. Furthermore, the particular curvature referred to is such as to well'adapt the clamp to cooperate with articles of widely varying sizes, a clamp automatically compensating for variations in size through the movable jaw, partaking of positions appropriate to the size of the article to be clamped.

; In practice, the'movable jaw may be gravity operated or spring operated or both combined. An important practical feature of the invention resides'in the/provision of'means for positively locking the movable jaw in clamping position; ofadditional or separate means for locking the article which is clamped between the jaws against inadvertent release should the jaws become separated for any reason whatever; through the provision on the fixed or movable jaw of a facing of friction-material to better adapt these jaws for the performance of the functions.

A further important practical feature of this invention consists in so constructing one or both of the jaws'of the clamp that an article when thrust directly against theface o'f the jaws, will cause the movable jaw to retract to admit the article between the jaws,

whereby the necessity of longitudinal movement of the article to introduce it between the jaws is obviated.

The foregoing features and others which will be apparent from the hereinafter detailed description result in a high clas article of pronounced merit adapted for widely varying uses and free from the objections heretofore found in prior cam action clamps.

The accompanying drawing illustrates the invention 1n different practical forms, but

" the constructions therein shown are to be unof ret ainingmember.

Figure 4 is a fragmental view correspondmg to-Fig. 1,'but1ll-ustrat1nga modified form of spring actuating means for .the movable jaw, as well as locking means for said aw.

.The clamp of the present invention comprises a suitable base plate 1 pr videdat on EllClWltll aright angle flange jaw indicated at 2. The flange jaw 2 may. extend uninterruptedly for'the full. width of the plate 1 or 7 it may be cut away asshown at 3' torender the structure lighter in weight. It isdesirable, however, that the flange 2 be relatively extensive, so as to-provlde a long bearing surface for the article 4 to be clamped and retained in position by the clamp.

1 The flange 2 constitutes a fixed jaw'of the clamp. The movable jaw designated 5 in the drawings is mounted on a pivot 6 suitably associated with the plate 1. As shown, the jaw .5 is in the form of a face plate 7 provided witha flenge 8 and having a hub or boss 9 in the vicinity of the pivot. The pivot 6 extends through the boss and is anchored to the base plate 1 in-a manner to allow free pivotal movementofthe jaw 5 about the pivot 6. I referably employ a relatively deep flange 8 and a correspondingly deep bossjor hub 9, so 7 that the boss will provide an extensive bear ing surface on the pivot and thus preclude lost motion during operation of the clamp;

1 The relatively large boss, moreover, provides a .goodbearing surface with the forwardqface of the plate 1 and thus guides the pivotal movement of the jaw 5, so that the movement iszsmooth and not wobbly. The ",lampin'gface 10 of the jaw 5 is curved on progressive radii to form a cam surface with reference to the fixed'jaw and this surface may be faced as indicated at 11. with suitable H friction materialsuch as fibre, rubber or the 0. i

ike. Similar friction material may be assoassembly.

ciated with the coacting face of the aw 2 although in practice I have found that this is not necessary. The friction material 11 may be applied merelyto the face 10 or may be 7 caused to entirely embrace the flange 8. This latter arrangement is avalled of 1n the lnterest of economy of manufacture and ease of It will is notched as indicated at 12, so that the facing will not have a tendency to come off, but will be retained in position on said flange. Par:

iicular attention is calledto the cut away,

beveled or sloping edge it at the forward edge of the aw 8. This provldes a re-entrant mouth for the entrance of an article between the jaws; Thus if an article such as indicated at a is forced againstthe open side ofthe space between the jaws, the reentrantmouth L rovi led by 5 to be retracted to permit the entry ofthe article i by direct pressureof the article against the jaw. The outer edge, of the jaw 2 froay be similarly beveled, although in prac-.

tice, I do not find thisnecessaryp i The clamp as thus far defined may be used complete in which event the jaw '5. will act ,by, however, add. addigravity. 1 preferably, tional features which will nowbe described.

In Figures 1 and 2,,Ih'ave shown acatch or latch 15 associatedwith.v theqjaw 2,. Th s latch is adapted to be-normally forced by a spring 16 into a position tooverlie a portion of the space between the jaws so as to posi tively retain an article between the aws. A

I simplified and more economical form of latch A 16 in Fig. 3, wherein the entire latch is in the form of aleaf spring provided with a suitable nose 17. This nose: .may be the movable jaw also retract-ed simultaneous-o is indicated at retracted as indicated in Fig. 3 and 1 by. merely pressing the articles in the the bevel 14; will cause the edge be noted, however,-that the flange 8 I direction of the-opening between the jaws.

If it is desired to make the jaw 5 spring actuated, this may accomplished indiffers ent-ways, for example, as indicated 1n Figures 1, 2 and 1. In

able jaw and' the other end secured by a pin 20 to an adjusting dislr21. This adjusting: disk is freely movable about tlieaxis of the pivot and is provided with peripheral notches 22 with which a locking pawl 23 is adapted to cooperate. The spring may betensioned to the extent desired by merely rotating the disk sufficiently to place the-spring under tensionand the pawl 23 will thereupon engage with a juxtaposed notch 22 -to' lock the parts in adjustment.

, In'the structure of rig. 4, a' somewha't 'different arrangement is shown; The spring Figures 1 and 2, a spring 18 is coiled aroundthe boss or hub-x9 with one end 19 of the spring hooked over the mov-;

18 is coiled about the boss and one end 19* j of the spring is secured to the'movab'le jaw as in Fig.1. The opposite-end'of the spring,

however, is adapted to be engaged with stationary pins 23 carried by the back plate and the tension of the spring may be controlled by simply shifting the spring into cooperation with one or the other of the pins 23 to place the spring under the desired tension.

The movable jaw may be positively locked in gripping or clamping position by such means as indicated in Fig. 4. Here the base plate 1 is shown as provided with a bracket 24 having a tapped hole through which a set screw 25 is operable. The set screw 25 is provided with a wing head 26 and after the part 4 is clamped in position, the screw 25 may be tightened to positively lock the movable jaw against movement and thus preclude any chance of removal of the article a until the screw 25 is retracted.

It will appear from the foregoing detailed description of the present invention that the invention provides for adjustable tension and does not depend entirely upon the gravity member but has the advantage of both gravity and adjustable tension. Furthermore,

I the entrance of the article into clamped position may be effected both through the bottom and by front pressure when desired. The latch at the front prevents accidental displacement and objects of any shape susceptible of being positioned between the fixed and movable jaws can be clamped in place by the structure which'I have described. The friction facings may be made removable or replaceable or may be vulcanized or otherwise secured directly to the member with which they cooperate. Furthermore when an arti cle is clamped in place, it is held by what may be termed a threepoint contact pressure be ing applied at one point in the length of the article between two or more other points at either side of the point of application of pressure. The tendency of the article therefore to sway and thus work loose or slide with respect to the clamp parts is entirely overcome.

In practice, the fiange2 which constitutes the fixed jaw of the device may have a plane or flat face and it has been thus described. I may, however, add to'the outer end of the jaw a small right angle flange 2 extending in the direction of the movable jaw. The purpose of this flange is to facilitate the grip ping of articles of such size as will not entirely enter between the jaws but will rather project outside of the jaws. The flange 2 provides a better contact for such articles and assures the tighter gripping of the same. The flange 2 is desirable even with small articles for in many uses it obviates the necessity or desirability of employing the latches 15 or 17.

Having thus fully described the invention, what I claim as new and desire to secure by Letters Patent is:

1. An automatic clamp embodying a base provided thereon with a forwardly projecting flange constituting a: fixed jaw, a pivot eX-' tending forwardly'from a point in the base remote from the fixed jaw, an arm having a rearwardly extending hub embracing the pivot and spacingthe arm from the base, a rearwardly extending flange, constituting a movable aw,- formed on the arm and having a curved cam shapedclamping face positionediin opposed relation to the fixed jaw to provide between the jaws a recess to receive an article to'be clamped, and a spring coiled about'said hub between'the base and the arm with one end of the spring secured to the arm and the other end of the spring anchored,

withrespect to the base, said spring being.

month through which articles may be forced I into the space between-the jaws, said bevel.

being shaped to cause retract-ion of the movable'jaw when an article is forced into the reentrant mouth to permit entrance of said article into the mouth, a spring coiled about the pivot of the movablejaw with one end of the spring secured to said aw,-and means for anchoring the opposite end of the spring with the spring under varying degrees of tension.

3. An automatic clamp embodying a suitable base provided thereonwith a fixed aw, a movable jaw mounted for pivotal movement on the base and having acurved cam shaped clamping face positioned in opposed relation to the fixed jaw to provide between the clamping faces of the fixed and movable jaws a recess to receive an article to be clamped, at least one of said jaws being beveled at the open side of said recess to provide a reentrant mouth through which articles may be forced into the space betweenthe jaws, said bevel being shaped to cause retraction of the movable jaw when an artieleis forced into the,

reentrant mouth to permit entrance of said article into the mouth, and a latch normally extending at'least partially across the reentrant mouth to preclude inadvertent .displacement of an article positioned in said month, said latch being retractable when it is desired to remove the article.

4:. An automatic clamp embodying a suitable base provided thereon, with a fixed jaw,

a movable jaw mounted for pivotal movement on the base and having a curved cam shaped clamping face positioned in opposed relation to the fixed jaw to provide between the clamping faces of the fixed and movable jaws a recess to receive an article to be clamped, at

least one of said jaws being beveled at the open side of said recess to provide a reentrant mouth through which articles maybe forced into the space between the jaws, said bevel ail to cause retraction ofthe m0va= ble jaw when an article is forcedinto' the re-' entrant'mouth to permit entrance of said article into the mouth, a spring coiled about the pivot of the movable jaw with one end of the spring secured to said j aw, means for anchoring the opposite end of the spring with the spring under varying degrees of tension,

and a latch normally extending across the reentrant mouth to preclude inadvertent re-.

lease ofthe article through said mouth.

- 5. An automatic clamp embodying a suitable base provided thereon with a fixed jaw, a movable jaw mounted for pivotal movement on the baseon a fixed axis and having a curved cam shaped. clamping face positioned in opposed relation to the fixed jaw to provide between the clamping faces of the fixed and movable aws a recess to receive an article to be clamped, at least oneof said jaws being beveled at the open side of said recess to provide a reentrant mouththrough which articles maybe forced into the space between the aws, sa1d bevel being shaped to cause re traction of the movable jaw when an article is forced into the reentrant mouth to permit entrance of'said article into the month, and

ieans for positively locking the movable jaw against rotative movement on saidfixed axis and in clamped position with respectto said article. I i I In testimony whereof I have signed the foregoing specification.

ALBERT 1; SGHIFF. 

